From 66caf51e13c9d05515045b134f60bae244dc56b9 Mon Sep 17 00:00:00 2001
From: Yuri Astrakhan <YuriAstrakhan@gmail.com>
Date: Thu, 28 Nov 2024 14:18:55 -0500
Subject: [PATCH] Automatic support for C-String literals

When `generate_cstr` is enabled, and the target rust version is >= 1.77, generate `c"..."` literals instead of the unsafe `from_bytes_with_nul_unchecked` calls.
---
 Cargo.lock                                    |  4 +-
 .../tests/expectations/tests/strings_cstr2.rs |  4 ++
 bindgen-tests/tests/headers/strings_cstr2.h   |  5 ++
 bindgen/codegen/mod.rs                        | 48 ++++++++++++-------
 bindgen/features.rs                           |  5 +-
 5 files changed, 45 insertions(+), 21 deletions(-)
 create mode 100644 bindgen-tests/tests/expectations/tests/strings_cstr2.rs
 create mode 100644 bindgen-tests/tests/headers/strings_cstr2.h

diff --git a/Cargo.lock b/Cargo.lock
index 251244184c..e5918dcc6d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -436,9 +436,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.60"
+version = "1.0.92"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dec2b086b7a862cf4de201096214fa870344cf922b2b30c167badb3af3195406"
+checksum = "37d3544b3f2748c54e147655edb5025752e2303145b5aefb3c3ea2c78b973bb0"
 dependencies = [
  "unicode-ident",
 ]
diff --git a/bindgen-tests/tests/expectations/tests/strings_cstr2.rs b/bindgen-tests/tests/expectations/tests/strings_cstr2.rs
new file mode 100644
index 0000000000..2ce21f4374
--- /dev/null
+++ b/bindgen-tests/tests/expectations/tests/strings_cstr2.rs
@@ -0,0 +1,4 @@
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+pub const MY_STRING_UTF8: &::std::ffi::CStr = c"Hello, world!";
+pub const MY_STRING_INTERIOR_NULL: &::std::ffi::CStr = c"Hello,";
+pub const MY_STRING_NON_UTF8: &::std::ffi::CStr = c"ABCDE\xFF";
diff --git a/bindgen-tests/tests/headers/strings_cstr2.h b/bindgen-tests/tests/headers/strings_cstr2.h
new file mode 100644
index 0000000000..2cd7e6222d
--- /dev/null
+++ b/bindgen-tests/tests/headers/strings_cstr2.h
@@ -0,0 +1,5 @@
+// bindgen-flags: --rust-target=1.77 --generate-cstr
+
+const char* MY_STRING_UTF8 = "Hello, world!";
+const char* MY_STRING_INTERIOR_NULL = "Hello,\0World!";
+const char* MY_STRING_NON_UTF8 = "ABCDE\xFF";
diff --git a/bindgen/codegen/mod.rs b/bindgen/codegen/mod.rs
index 943d8c7513..9f25369479 100644
--- a/bindgen/codegen/mod.rs
+++ b/bindgen/codegen/mod.rs
@@ -717,26 +717,38 @@ impl CodeGenerator for Var {
                     let len = proc_macro2::Literal::usize_unsuffixed(
                         cstr_bytes.len(),
                     );
+                    let cstr =
+                        if options.generate_cstr && rust_features.const_cstr {
+                            CStr::from_bytes_with_nul(&cstr_bytes).ok()
+                        } else {
+                            None
+                        };
 
-                    // TODO: Here we ignore the type we just made up, probably
-                    // we should refactor how the variable type and ty ID work.
-                    let array_ty = quote! { [u8; #len] };
-                    let cstr_ty = quote! { ::#prefix::ffi::CStr };
-
-                    let bytes = proc_macro2::Literal::byte_string(&cstr_bytes);
-
-                    if options.generate_cstr &&
-                        rust_features.const_cstr &&
-                        CStr::from_bytes_with_nul(&cstr_bytes).is_ok()
-                    {
-                        result.push(quote! {
-                            #(#attrs)*
-                            #[allow(unsafe_code)]
-                            pub const #canonical_ident: &#cstr_ty = unsafe {
-                                #cstr_ty::from_bytes_with_nul_unchecked(#bytes)
-                            };
-                        });
+                    if let Some(cstr) = cstr {
+                        let cstr_ty = quote! { ::#prefix::ffi::CStr };
+                        if rust_features.literal_cstr {
+                            let cstr = proc_macro2::Literal::c_string(&cstr);
+                            result.push(quote! {
+                                #(#attrs)*
+                                pub const #canonical_ident: &#cstr_ty = #cstr;
+                            });
+                        } else {
+                            let bytes =
+                                proc_macro2::Literal::byte_string(&cstr_bytes);
+                            result.push(quote! {
+                                #(#attrs)*
+                                #[allow(unsafe_code)]
+                                pub const #canonical_ident: &#cstr_ty = unsafe {
+                                    #cstr_ty::from_bytes_with_nul_unchecked(#bytes)
+                                };
+                            });
+                        }
                     } else {
+                        // TODO: Here we ignore the type we just made up, probably
+                        // we should refactor how the variable type and ty ID work.
+                        let array_ty = quote! { [u8; #len] };
+                        let bytes =
+                            proc_macro2::Literal::byte_string(&cstr_bytes);
                         let lifetime =
                             if true { None } else { Some(quote! { 'static }) }
                                 .into_iter();
diff --git a/bindgen/features.rs b/bindgen/features.rs
index 9991522497..174491fae0 100644
--- a/bindgen/features.rs
+++ b/bindgen/features.rs
@@ -159,7 +159,10 @@ define_rust_targets! {
         ptr_metadata: #81513,
         layout_for_ptr: #69835,
     },
-    Stable_1_77(77) => { offset_of: #106655 },
+    Stable_1_77(77) => {
+        offset_of: #106655,
+        literal_cstr: #117472,
+    },
     Stable_1_73(73) => { thiscall_abi: #42202 },
     Stable_1_71(71) => { c_unwind_abi: #106075 },
     Stable_1_68(68) => { abi_efiapi: #105795 },